Drush integration

I just reviewed this and its an interesting idea. One of the theories of this module is that it's a proxy and only downloads things as they are needed.

That said, I could see the benefit of the solution you provided in a few scenarios.

Anyone else have opinions on this proposal?

I think that would be a great addition

I wrote a similar script that can be used after configuring the module. Just 5 lines of PHP (just for other people who might be looking for this):

foreach (db_select('file_managed', 'f')->fields('f', array('uri'))->execute()->fetchCol() as $uri) {
  if(!file_exists($uri)) {
    drupal_http_request(file_create_url($uri));
  }
}

Note that depending on how many files there are this might take quite a while, and it might be (or will be) better to convert it to a drupal batch operation or something similar.

I think it is a good idea and wrote also on my side this drush command : see attached file.

I've tested SylvainM's patch and it seems to me that will be good. There were some files that couldn't be downloaded but I think it's site/server issue because I couldn't find those files.

@asrob, there are two proposals here: 1 is in a zip and 1 in a patch. Any chance you could review them both and compare/contrast?

I reviewed both proposals; the patch is created for stage_file_proy while the zip is a more generic approach.
I renamed the drush command to stage-file-proxy-dl instead of stage-file-proxy-download-all, since the drush command overview truncated the latter to stage-file-proxy-dow.

Committed to 7.x-1.x-dev. If someone would port this to D8, that would be awesome!

Here is a D8 patch

Tested the patch, it works great. Thanks for porting it SylvainM!